1. Field of the Invention
The present invention relates to the technology field of switch units, and more particularly to a rotary switch.
2. Description of the Prior Art
Rotary switches are often applied to electric equipment, especially for electric equipment with multistage functions, such as electric fans, lamps, washing machines etc. In addition, rotary switches can switch between multistage functions of the electric equipment by using an adjust button of the rotary switch.
Please refer to FIG. 1 and FIG. 2, where an exploded view and a stereo view of a conventional rotary switch are shown. As shown in FIG. 1 and FIG. 2, the conventional rotary switch 1′ consists of: an upper casing 10A′, a lower casing 10B′, a rotary unit 2′, a substrate 3′, a rotary retaining element 4′, two springs 5′, and a switch unit 6′; wherein the upper casing 10A′ and the lower casing 10B′ are provided with a first opening 11′ and a second opening 12′, respectively.
The rotary unit 2′, disposed between the upper casing 10A′ and the lower casing 10B′, is consisted of a rotary body 20′, a rotary disk 22′, a cam 21′, and a conductive member 23′. As FIG. 1 shows, the top of the cam 21′ is connected to the lower end of the rotary body 20′ via a through hole 31′ on the substrate 3′, and the bottom of the cam 21′ is embedded into the second opening 12′ of the lower casing 10B′. Moreover, the top end of the rotary body 20′ passes through the first opening 11′ so as to protrude out of the upper casing 10A′. For being suffering to the acting force from the springs 5′, the rotary retaining element 4′ props the rotary disk 22′ by embedding into any one rotary grooves 220′ formed around the side edge of the rotary disk 22′; so that, since the rotary disk 22′ is propped and retained by the rotary retaining element 4′, the two conductive protrusions 230′ of the conductive members 23′ would respectively electrically connect with two of a plurality of electrically-connecting regions 30′ formed on the substrate 3′.
Referring to FIG. 1 and FIG. 2 again, by the interlocking of at least one first lock member 100′ of the upper casing 10A′ and the second lock member 101′ of the upper casing 10B′, a switch housing is therefore formed so as to accommodate the rotary unit 2′, the substrate 3′, the rotary retaining element 4′, the springs 5′. Besides, the switch unit 6′ is attached to the bottom surface of the switch housing through the clamping of the two unit fixing members 104′.
Although the rotary switch 1′ shown in FIG. 1 and FIG. 2 has been widely used in various electric products, this conventional rotary switch 1′ has revealed some drawbacks and shortcomings in practical use; wherein the drawbacks and shortcomings showed by the rotary switch 1′ are as follows:    (1) Because the rotary switch 1′ is design to perform unidirectional rotation by single shaft, the maximum switching levels for the rotary switch 1′ merely reach to 16 levels. For some particular electric products, such rotary switch 1′ is still lack of enough switching levels.    (2) As FIG. 1 shows, the rotary body 20′ would rotate by an angle (for instance, 20°) when switching the rotary switch 1′ from one switching level to another one switching level, such that the rotary retaining element 4′ escapes out of one rotary grooves 220′ and subsequently embeds into another one rotary grooves 220′. However, since the rotary retaining element 4′ is embedded into the rotary grooves 220′ due to the acting force provided by the springs 5′, the rotary retaining element 4′ may not fully embed into the rotary grooves 220′ if the springs 5′ provides an uneven acting force to the rotary retaining element 4′; that would cause the conductive protrusions 230 of the conductive members 23 unable to precisely connect with two of a plurality of electrically-connecting regions 30′ formed on the substrate 3′, thereafter the functions of the electric product may not be switch smoothly and completely.
Accordingly, in view of the conventional rotary switch 1′ still include drawbacks, the inventor of the present application has made great efforts to make inventive research thereon and eventually provided a nanoparticle manufacturing system.